Interfacial-Assembly-Induced In Situ Transformation from Aligned 1D Nanowires to Quasi-2D Nanofilms.

As the dimensionality of materials generally affects their characteristics, thin films composed of low-dimensional nanomaterials, such as nanowires (NWs) or nanoplates, are of great importance in modern engineering. Among various bottom-up film fabrication strategies, interfacial assembly of nanoscale building blocks holds great promise in constructing large-scale aligned thin films, leading to emergent or enhanced collective properties compared to individual building blocks. As for 1D nanostructures, the interfacial self-assembly causes the morphology orientation, effectively achieving anisotropic electrical, thermal, and optical conduction. However, issues such as defects between each nanoscale building block, crystal orientation, and homogeneity constrain the application of ordered films. The precise control of transdimensional synthesis and the formation mechanism from 1D to 2D are rarely reported. To meet this gap, we introduce an interfacial-assembly-induced interfacial synthesis strategy and successfully synthesize quasi-2D nanofilms via the oriented attachment of 1D NWs on the liquid interface. Theoretical sampling and simulation show that NWs on the liquid interface maintain their lowest interaction energy for the ordered crystal plane (110) orientation and then rearrange and attach to the quasi-2D nanofilm. This quasi-2D nanofilm shows enhanced electric conductivity and unique optical properties compared with its corresponding 1D geometry materials. Uncovering these growth pathways of the 1D-to-2D transition provides opportunities for future material design and synthesis at the interface.

Root endophyte-mediated alteration in plant H2O2 homeostasis regulates symbiosis outcome and reshapes the rhizosphere microbiota.

Endophytic symbioses between plants and fungi are a dominant feature of many terrestrial ecosystems, yet little is known about the signaling that defines these symbiotic associations. Hydrogen peroxide (H2O2) is recognized as a key signal mediating the plant adaptive response to both biotic and abiotic stresses. However, the role of H2O2 in plant-fungal symbiosis remains elusive. Using a combination of physiological analysis, plant and fungal deletion mutants, and comparative transcriptomics, we reported that various environmental conditions differentially affect the interaction between Arabidopsis and the root endophyte Phomopsis liquidambaris, and link this process to alterations in H2O2 levels and H2O2 fluxes across root tips. We found that enhanced H2O2 efflux leading to a moderate increase in H2O2 levels at the plant-fungal interface is required for maintaining plant-fungal symbiosis. Disturbance of plant H2O2 homeostasis compromises the symbiotic ability of plant roots. Moreover, the fungus-regulated H2O2 dynamics modulate the rhizosphere microbiome by selectively enriching for the phylum Cyanobacteria, with strong antioxidant defenses. Our results demonstrated that the regulation of H2O2 dynamics at the plant-fungal interface affects the symbiotic outcome in response to external conditions and highlight the importance of the root endophyte in reshaping the rhizosphere microbiota.

Microchemical Engineering in a 3D Ordered Channel Enhances Electrocatalysis.

The kinetics of electrode reactions including mass transfer and surface reaction is essential in electrocatalysis, as it strongly determines the apparent reaction rates, especially on nanostructured electrocatalysts. However, important challenges still remain in optimizing the kinetics of given catalysts with suitable constituents, morphology, and crystalline design to maximize the electrocatalytic performances. We propose a comprehensive kinetic model coupling mass transfer and surface reaction on the nanocatalyst-modified electrode surface to explore and shed light on the kinetic optimization in electrocatalysis. Moreover, a theory-guided microchemical engineering (MCE) strategy has been demonstrated to rationally redesign the catalysts with optimized kinetics. Experimental measurements for methanol oxidation reaction in a 3D ordered channel with tunable channel sizes confirm the calculation prediction. Under the optimized channel size, mass transfer and surface reaction in the channeled microreactor are both well regulated. This MCE strategy will bring about a significant leap forward in structured catalyst design and kinetic modulation.

A Metallic Ion-Induced Self-Assembly Enabling Nanowire-Based Aerogels.

The controlled assembly of nanowires is one of the key challenges in the development of a range of functional 3D aerogels with unique physicochemical properties for practical applications. However, the deep understanding of the dynamic assemble process for fabricating nanowire aerogels remains elusive. Herein, a facile strategy is presented for the metallic ion-induced assembly of nanowires into macroscopic aerogels via a solution-based process. This method enables the interconnecting between polymer-decorated nanowires via metallic coordination, resulting in plenty of nanowire bundles with the same orientation. Besides, the coordinated binding strength of nanowires with different metallic ions is also discussed. The assembly mechanism that the metallic ions induced dynamic behavior of nanowires is revealed via molecular dynamics theoretical evaluation. These findings benefit for constructing nanowire-based aerogels with unique structural features and multi-function, which pave new opportunities for other material systems.

Radial Nanowire Assemblies under Rotating Magnetic Field Enabled Efficient Charge Separation.

Developing efficient charge separation strategies is essential to achieve high-power conversion efficiency in the fields of chemistry, biology, and material science. Herein, we develop a facile strategy for fabrication of unique wafer-scale radial nanowire assemblies by exploiting shear force in rotary solution. The assembly mechanism can be well revealed by the large-scale stochastic dynamics simulation. Free electrons can be rapidly generated to produce quantitatively tunable current output when the radial nanowire assemblies rotate under the magnetic field. Moreover, the photoconductive performance of the radial semiconductor nanowire assemblies can be remarkably enhanced as the electron-hole recombination was retrained by the efficient charge separation under the rotating magnetic field. Such large-scale unique nanowire assemblies will facilitate the design of an efficient charge separation process in biosystem, sensors, and photocatalysis.

Ordered Nanostructure Enhances Electrocatalytic Performance by Directional Micro-Electric Field.

Designing high-efficiency catalyst is at the heart of a transition to future renewable energy systems. Great achievements have been made to optimize thermodynamics to reduce energetic barriers of the catalytic reactions. However, little attention has been paid to design catalysts to improve kinetics to enrich the local concentration of reactant molecules surrounding electrocatalysts. Here, we find that well-designed nanocatalysts with periodic structures can optimize kinetics to accelerate mass-transport from bulk electrolyte to the catalyst surface, leading to the enhanced catalytic performance. This achievement stems from regulation of the surface reactant flux due to the gradient of the microelectric field directing uniformly to the nearest catalyst on ordered pattern, so that all of the reactant molecules are utilized sufficiently for reactions, enabling the boost of the electrocatalytic performance. This novel concept is further confirmed in various catalytic systems and nanoassemblies, such as nanoparticles, nanorods, and nanoflakes.

Real-Time Probing of Nanowire Assembly Kinetics at the Air-Water Interface by In†Situ Synchrotron X-Ray Scattering.

Although many assembly strategies have been used to successfully construct well-aligned nanowire (NW) assemblies, the understanding of their assembly kinetics has remained elusive, which restricts the development of NW-based device and circuit fabrication. Now a versatile strategy that combines interfacial assembly and synchrotron-based grazing-incidence small-angle X-ray scattering (GISAXS) is presented to track the assembly evolution of the NWs in real time. During the interface assembly process, the randomly dispersed NWs gradually aggregate to form small ordered NW-blocks and finally are constructed into well-defined NW monolayer driven by the conformation entropy. The NW assembly mechanism can be well revealed by the thermodynamic analysis and large-scale molecular dynamics theoretical evaluation. These findings point to new opportunities for understanding NW assembly kinetics and manipulating NW assembled structures by bottom-up strategy.

Depletion of protective microbiota promotes the incidence of fruit disease.

Plant-associated microbiomes play important roles in plant health and productivity. However, despite fruits being directly linked to plant productivity, little is known about the microbiomes of fruits and their potential association with fruit health. Here, by integrating 16S rRNA gene, ITS high-throughput sequencing data, and microbiological culturable approaches, we reported that roots and fruits (pods) of peanut, a typical plant that bears fruits underground, recruit different bacterial and fungal communities independently of cropping conditions and that the incidence of pod disease under monocropping conditions is attributed to the depletion of Bacillus genus and enrichment of Aspergillus genus in geocarposphere. On this basis, we constructed a synthetic community (SynCom) consisting of three Bacillus strains from geocarposphere soil under rotation conditions with high culturable abundance. Comparative transcriptome, microbiome profiling, and plant phytohormone signaling analysis reveal that the SynCom exhibited more effective Aspergillus growth inhibition and pod disease control than individual strain, which was underpinned by a combination of molecular mechanisms related to fungal cell proliferation interference, mycotoxins biosynthesis impairment, and jasmonic acid-mediated plant immunity activation. Overall, our results reveal the filter effect of plant organs on the microbiome and that depletion of key protective microbial community promotes the fruit disease incidence.

Root Endophyte-Manipulated Alteration in Rhizodeposits Stimulates Claroideoglomus in the Rhizosphere to Enhance Drought Resistance in Peanut.

Drought dramatically affects plant growth and yield. A previous study indicated that endophytic fungus Phomopsis liquidambaris can improve the drought resistance of peanuts, which is related with the root arbuscular mycorrhizal fungi (AMF) community; however, how root endophytes mediate AMF assembly to affect plant drought resistance remains unclear. Here, we explored the mechanism by which endophytic fungus recruits AMF symbiotic partners via rhizodeposits to improve host drought resistance. The results showed that Ph. liquidambaris enhanced peanut drought resistance by enriching the AMF genus Claroideoglomus of the rhizosphere. Furthermore, metabolomic analysis indicated that Ph. liquidambaris significantly promoted isoformononetin and salicylic acid (SA) synthesis in rhizodeposits, which were correlated with the increase in Claroideoglomus abundance following Ph. liquidambaris inoculation. Coinoculation experiments confirmed that isoformononetin and SA could enrich Claroideoglomus etunicatum in the rhizosphere, thereby improving the drought resistance. This study highlights the crucial role of fungal consortia in plant stress resistance.

Fungal endophyte promotes plant growth and disease resistance of Arachis hypogaea L. by reshaping the core root microbiome under monocropping conditions.

Fungal endophytes play critical roles in helping plants adapt to adverse environmental conditions. The root endophyte Phomopsis liquidambaris can promote the growth and disease control of peanut plants grown under monocropping systems; however, how such beneficial traits are produced is largely unknown. Since the plant endophytic microbiome is directly linked to plant growth and health, and the composition of which has been found to be potentially influenced by microbial inoculants, this study aims to clarify the roles of root endophytic bacterial communities in P. liquidambaris-mediated plant fitness enhancement under monocropping conditions. Here, we found that P. liquidambaris inoculation induced significant changes in the root bacterial community: enriching some beneficial bacteria such as Bradyrhizobium sp. and Streptomyces sp. in the roots, and improving the core microbial-based interaction network. Next, we assembled and simplified a synthetic community (SynII) based on P. liquidambaris-derived key taxa, including Bacillus sp. HB1, Bacillus sp. HB9, Burkholderia sp. MB7, Pseudomonas sp. MB2, Streptomyces sp. MB6, and Bradyrhizobium sp. MB15. Furthermore, the application of the simplified synthetic community suppressed root rot caused by Fusarium oxysporum, promoted plant growth, and increased peanut yields under continuous monocropping conditions. The resistance of synII to F. oxysporum is related to the increased activity of defense enzymes. In addition, synII application significantly increased shoot and root biomass, and yield by 35.56%, 81.19%, and 34.31%, respectively. Collectively, our results suggest that the reshaping of root core microbiota plays an important role in the probiotic-mediated adaptability of plants under adverse environments.

Hyphosphere microorganisms facilitate hyphal spreading and root colonization of plant symbiotic fungus in ammonium-enriched soil.

Anthropogenic nitrogen inputs lead to a high ammonium (NH4+)/nitrate (NO3-) ratio in the soil, which restricts hyphal spreading of soil fungi. Access of symbiotic fungi to roots is a prerequisite for plant-fungal interactions. Hyphosphere bacteria protect fungi from environmental stress, yet the impact of hyphosphere bacteria on adaptation of host fungi to NH4+-enriched conditions remains unclear. By developing soil microcosm assays, we report that a plant-symbiotic fungus, Phomopsis liquidambaris, harbors specific hyphosphere bacteria that facilitate hyphal spreading and assist in the root colonization in NH4+-enriched soil. Genetic manipulation, 16S rRNA gene analysis and coinoculation assays revealed that the genus Enterobacter was enriched in the hyphosphere of NH4+-sensitive wild-type compared to NH4+-preferring nitrite reductase-deficient strain. The representative Enterobacter sp. SZ2-promoted hyphal spreading is only evident in nonsterilized soil. We further identified an increased abundance and diversity of ammonia-oxidizing archaea (AOA) and a synchronously decreased NH4+:NO3- ratio following SZ2 inoculation. Microbial supplementation and inhibitor assays showed that AOA-mediated reduction in NH4+:NO3- ratio is responsible for SZ2-enhanced fungal adaptation to NH4+-enriched conditions. The Ph. liquidambaris-Enterobacter-AOA triple interaction promoted rice growth in NH4+-enriched soil. Our study reveals the essential role of hyphosphere microorganism-based hyphal spreading in plant-fungal symbiosis establishment within nitrogen-affected agroecosystems.

Graphene oxide noncovalent photosensitizer and its anticancer activity in vitro.

Graphene oxide (GO) was investigated as a potential drug-delivery system due to its special properties and biocompatibility. Thus far, little has been done to use GO as a photosensitive drug-delivery system and to explore its anticancer activity in vitro in photodynamic therapy applications. Here, a novel GO-hypocrellin A (GO-HA) hybrid was prepared by a simple noncovalent method and its photodynamic activity was studied for the first time. The results showed that an efficient loading amount of HA on GO was as high as 1.0 mg mg(-1) and the stability of the hybrid was superior to that of the free hypocrellin A in aqueous solution. Furthermore, GO-HA can be excited by irradiation with light of appropriate wavelength to generate singlet oxygen, and in vitro experiments illustrated that GO-HA was efficiently taken up by tumor cells, and that light irradiation of such impregnated cells resulted in significant cell death. Thus, these properties of GO-HA could possibly make it especially promising for use in clinical photodynamic therapy.

Water-Induced Chiral Separation on a Au(111) Surface.

Facing the scientific question of the origin of chirality in life, water is considered to play a crucial role in driving many biologically relevant processes in vivo. Water has been demonstrated in vitro to be related to chiral generation, amplification, and inversion, while the underlying mechanism is still not fully understood. Real-space evidence at the single-molecule level is thus urgently required to understand the role of water molecules in biomolecular chirality related issues. Herein, we choose one of the RNA bases, the biomolecule uracil (U), which self-assembles into racemic hydrogen-bonded structures. Upon water exposure, surprisingly, racemic structures could be transformed to homochiral water-involved structures, resulting in an unexpected chiral separation on the surface. The origin of chiral separation is due to preferential binding between water and the specific site of U molecules, which leads to the formation of the energetically most favorable homochiral (U-H2O-U)2 cluster as seed for subsequent chiral amplification. Such a water-driven self-assembly process may also be extended to other biologically relevant systems such as amino acids and sugars, which would provide general insights into the role that water molecules may play in the origin of homochirality in vivo.

4-(4-Pyrid-yl)pyridinium penta-aqua(pyridazine-4,5-dicarboxyl-ato)praseodymate(III).

In the title complex, (C(10)H(9)N(2))[Pr(C(6)H(2)N(2)O(4))(2)(H(2)O)(5)], the Pr atom is nine-coordinated by nine O atoms from two pyridazine-4,5-dicarboxyl-ate anions and five water mol-ecules. It is noteworthy that there is a protonated bipyridine mol-ecule in the structure. Inter-molecular O-H⋯O, O-H⋯N and N-H⋯N hydrogen bonds are present, resulting in a three-dimensional network.

Rat colitis induced by intrathecal injection of substance P.

The aim of this study was to, from the point of neurogenic inflammation, explore the pathogenesis of colitis and to provide direct evidence for the neurogenic colitis hypothesis. Male Sprague-Dawley rats (180-220 g) anesthetized with chloral hydrate were intrathecally (ith) implanted with polyethylene-10 (PE-10) catheter to reach the spinal cord T12-L5 level. Substance P (SP) was ith injected once a day for 14 d. The disease active index (DAI) score was calculated by rat body weight and stool. The macroscopic and HE staining-microscopic pathologies of colon/spinal tissue were evaluated. By immunofluorescence staining, the protein expression of a pro-inflammatory cytokine, migration inhibitory factor (MIF), in colon tissue was detected and was semi-quantitatively analyzed. The results showed that in the colon tissue, inflammation was dose-dependently aggravated by ith SP 10 µ and 20 µ, whereas in the spinal tissue, only slight edema and congestion were seen in SP 20 µ group. The MIF protein of colon tissue was increased in ith SP 10 µ and 20 µ groups (P<0.05, P<0.01 as compared to normal saline group respectively), but in the spinal tissue, there was no obvious MIF protein expression either in SP groups or in normal saline group. Pretreatment with neurokinin-1 (NK1) receptor antagonist ([D-Pro2, D-Trp7, 9] -SP, 22.4 µ, ith, 10 min before ith SP) prolonged the latency of DAI rising and reduced the DAI amplitude, as well as prevented the high MIF expression induced by ith SP. These results suggest that rat colitis can be induced by direct SP stimulation in lumbar spine via activating central NK1 receptor; and that colonic MIF is possibly one of the inflammatory factors involved in this pathogenesis. These data provide a reasonable support to the hypothesis of colitis being a neurogenic inflammation. In addition, a potential clinical significance for the finding that higher concentration of spinal SP can induce colitis via NK1 receptor is discussed.

Clinical observation on the treatment of post-cesarean hypogalactia by auricular points sticking-pressing.

OBJECTIVE: To explore the effect of auricular points sticking-pressing (APSP) in treating post-cesarean hypogalactia (PCH). METHODS: A randomized, controlled, single-blinded clinical trial on 116 patients with PCH was carried out. They were equally assigned to the treatment group and the control group. The treatment group received APSP, with the pellets pressed for 4 times daily, while the control group was only asked to do lactation to meet infant demand. The therapeutic efficacy and the changes in scores of traditional Chinese medicine (TCM) syndrome, volume of milk secretion, supplementary feeding and serum level of prolactin (PRL) in the two groups were estimated and compared after the patients had been treated for 5 days. RESULTS: The cured and markedly effective rate in the treatment group was 89.7%, which was significantly higher than that in the control group (27.6%, P<0.05), 95% CI (0.1543, 0.2527). The improvement of TCM syndrome, elevation of milking volume, decrease of the supplementary feeding and increase of PRL level revealed in the treatment group were all superior to those in the control group, showing statistical significance (P<0.01). CONCLUSION: APSP shows an apparent efficacy in treating PCH and is worthy of application in clinical practice.

[Fluorescence spectroscopic study of interaction between Fe-protoporphyrin in myoglobin and Cu(II) ions].

In this paper, the interaction between Cu(II) ions and Fe-protoporphyrin in horse-heart myoglobin (FePP-Mb) was studied. As a result, some of the Fe(II) ions in FePP-Mb were found to be replaced by Cu(II) ions forming CuPP-Mb, by adding Cu(II) ions into the myoglobin solution. The interaction became stronger when adding more Cu(II) ions into the myoglobin solution. By studying the metal ions' interaction with myoglobin proteins as macromolecules and discussing the interaction mechanism, this work provides a theoretical basis for the further study of hazardous metal ions' interaction with the human body and its mechanism. The fluorescence spectroscopic method used in this study has higher sensitivity than the ordinary UV and CD methods.

Interleukin-17 SNPs and serum levels increase ulcerative colitis risk: a meta-analysis.

AIM: To investigate the associations of interleukin-17 (IL-17) genetic polymorphisms and serum levels with ulcerative colitis (UC) risk. METHODS: Relevant articles were identified through a search of the following electronic databases, excluding language restriction: (1) the Cochrane Library Database (Issue 12, 2013); (2) Web of Science (1945-2013); (3) PubMed (1966-2013); (4) CINAHL (1982-2013); (5) EMBASE (1980-2013); and (6) the Chinese Biomedical Database (1982-2013). Meta-analysis was conducted using STATA 12.0 software. Crude odds ratios and standardized mean differences (SMDs) with corresponding 95% confidence intervals (CIs) were calculated. All of the included studies met all of the following five criteria: (1) the study design must be a clinical cohort or a case-control study; (2) the study must relate to the relationship between IL-17A/F genetic polymorphisms or serum IL-17 levels and the risk of UC; (3) all patients must meet the diagnostic criteria for UC; (4) the study must provide sufficient information about single nucleotide polymorphism frequencies or serum IL-17 levels; and (5) the genotype distribution of healthy controls must conform to the Hardy-Weinberg equilibrium (HWE). The Newcastle-Ottawa Scale (NOS) criteria were used to assess the methodological quality of the studies. The NOS criteria included three aspects: (1) subject selection: 0-4; (2) comparability of subjects: 0-2; and (3) clinical outcome: 0-3. NOS scores ranged from 0 to 9, with a score ≥ 7 indicating good quality. RESULTS: Of the initial 177 articles, only 16 case-control studies met all of the inclusion criteria. A total of 1614 UC patients and 2863 healthy controls were included in this study. Fourteen studies were performed on Asian populations, and two studies on Caucasian populations. Results of the meta-analysis revealed that IL-17A and IL-17F genetic polymorphisms potentially increased UC risk under both allele and dominant models (P < 0.001 for all). The results also showed that UC patients had higher serum IL-17 levels than healthy controls (SMD = 5.95, 95%CI: 4.25-7.65, P < 0.001). Furthermore, serum IL-17 levels significantly correlated with the severity of UC (moderate vs mild: SMD = 2.59, 95%CI: 0.03-5.16, P < 0.05; severe vs mild: SMD = 7.09, 95%CI: 3.96-10.23, P < 0.001; severe vs moderate: SMD = 5.84, 95%CI: 5.09-6.59, P < 0.001). The NOS score was ≥ 5 for all of the included studies. Based on the sensitivity analysis, no single study influenced the overall pooled estimates. Neither the Begger's funnel plots nor Egger's test displayed strong statistical evidence for publication bias (IL-17A/F genetic polymorphisms: t = -2.60, P = 0.019; serum IL-17 levels: t = -1.54, P = 0.141). CONCLUSION: The findings strongly suggest that IL-17A/F genetic polymorphisms and serum IL-17 levels contribute to the development and progression of UC.